Various forms of folding skis and knockdown skis have been heretofore designed and other forms of skis have been provided with retractable undersurface projections for use in braking and also for use in moving forwardly up a slope, the projections, when extended, acting as brakes to prevent rearward sliding of the skis. Examples of various forms of these types of skis are disclosed in U.S. Pat. Nos. 2,224,897, 2,302,478, 3,332,404, 2,791,435, 3,689,093 and 3,873,108.
However, when it is desired to engage in cross-country skiing, common practice dictates the use of carefully applied special waxes to the undersurfaces of the skis or the use of special skis with "fish scale" bottoms or mohair strips which mainly comprise the grouping known as "no wax" skis. The various current forms of "no wax" skis reduce the ability of the skis to slide forwardly with minimum resistance and the use of special waxes is time consuming and has the disadvantage that even carefully applied special waxes loose their efficiency after short periods of use.
Accordingly, a need exists for a ski which may be efficiently, comfortably and pleasurably used for cross-country skiing.